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The interplay of segmental with prosodic structure in phonetic planning: Evidence from apraxia of speech

Dr. Ingrid Aichert & Prof. Dr. Wolfram Ziegler


Project period: 2014-2019

Adult speakers rely on acquired implicit knowledge about how to move their articulators for the production of speech sounds. This knowledge is considered to be embodied in “phonetic plans” which provide the basis of fluent, automated speech. A most influential theory of language production proposed by Levelt & coworkers conceives phonetic plans as linear strings of motor primitives representing the gestural scores of frequent syllables.

This project is based on the premise that apraxia of speech, an adult motor speech disorder, results from a deconstruction of phonetic plans and therefore provides a window into the internal make-up of learned speech motor behaviour. Evidence from our earlier research suggests that phonetic plans have a hierarchically nested architecture in which the different word form layers, from gestures to metrical feet, are interlaced.

Our new project will focus specifically on the interplay between prosodic and segmental factors in phonetic planning. Two experiments are devised to test the hypothesis that segmental and metrical properties interact in their impact on apraxic failure. We expect to learn more about how fine-grained phonetic detail interleaves with speech rhythm in normal and disordered speech motor planning and in the re-learning of articulatory skills.

  dfg supported by the German Research Foundation (DFG) ZI 469 / 14-1


  • Aichert, I., Späth, M. & Ziegler, W. (2016). The Role of Metrical Information in Apraxia of Speech. Perceptual and Acoustic Analyses of Word Stress. Neuropsychologia, 82, 171-178.
  • Aichert, I., Lehner, K., Falk, S., Späth, M., Ziegler, W. (2019). Do Patients with Neurogenic Speech Sound Impairments Benefit from Auditory Priming with a Regular Metrical Pattern? Journal of Speech, Language, and Hearing Research, 62, 3104-3118.
  • Aichert, I., Lehner, K., Falk, S., Späth, M., Franke, M. & Ziegler, W. (2019). In Time with the Beat: Entrainment in Patients with Phonological Impairment, Apraxia of speech and Parkinson’s disease. Stem-, Spraak- en Taalpathologie, 24, 57.
  • Ziegler, W. & Aichert, I. (2015). How Much Is a Word? Predicting Ease of Articulation Planning from Apraxic Speech Error Patterns. Cortex, 69, 24-39.
  • Ziegler, W., Aichert, I. & Staiger, A. (2017). When Words Don't Come Easily: A Latent Trait Analysis of Impaired Speech Motor Planning in Patients with Apraxia of Speech. Journal of Phonetics, 64, 145-155.
  • Ziegler, W., Lehner, K., Pfab, J. & Aichert, I. (2020). The Nonlinear Gestural Model of Speech Apraxia: Clinical Implications and Applications. Aphasiology,